(Image: Roger Harris/SPL)" title="Uranus is not as lonely as we thought (Image: Roger Harris/SPL)">
Object: A 60-kilometre-wide asteroid
Location: 3 billion kilometres ahead of Uranus, in the planet's L4 Lagrange point
Uranus has a forbidden friend. The first asteroid to share the planet's orbit has been found, despite claims that Jupiter's mighty gravity should steal such companions away.
The finding hints that more of these asteroids, called Trojans, lurk around unexpected worlds. Since Trojans don't always stay in place, finding new ones improves our picture of how space rocks migrate around the solar system. It also means there may be super-sized Trojans sharing orbits with massive exoplanets.